In situ laser heating and radial synchrotron x-ray diffraction in a diamond anvil cell

Abstract

TitleIn situ laser heating and radial synchrotron X-ray diffraction in a diamond anvil cell Permalink https://escholarship.org/uc/item/9mp2r6b4

In situ phase transformation and deformation of iron at high pressure and temperature

“…31,32 A setup for single-sided in-situ laser heating of a DAC in radial diffraction geometry was recently implemented on this beamline. 5 In order to remotely change pressure, we constructed an rDAC holding frame which is compatible with various radial diffraction cells. The device consists of a frame-body, housing the rDAC in use, a membrane, and a base plate to constrain the piston against the cylinder (Figure 2).…”

“…36 Laser heating was performed applying a fiber IR laser and optical set-up for radial diffraction. 5 Temperature was measured by fitting its spectral glow to a Planck function. 32 In the first run (A) pressure was increased at ambient temperature in ~ 0.25 GPa increments taking in-situ diffraction images at each step up to a pressure of ~22 GPa at which point the sample was fully converted to the hcp phase.…”

“…In order to expand rDAC experiments to the high-temperature regime, an in-situ laser-heating system for radial diffraction geometry has been developed at the Advanced Light Source (ALS) of the Lawrence Berkeley Laboratory (LBL). 5 Previously, pressure/stress increase in rDACs has been controlled through load screws pushing the piston of the rDAC into its cylinder. This requires manual intervention and is incompatible with in-situ observations of the effects of pressure and stress increase at high-temperature.…”

Experimental method for in situ determination of material textures at simultaneous high pressure and high temperature by means of radial diffraction in the diamond anvil cell

“…There are multiple avenues one might take to study plastic deformation under simultaneous high pressure, high temperature while probing the sample using in situ x-ray diffraction: ͑a͒ in a large volume press ͑LVP͒ such a Drickamer 13 or the multianvil device, 14 ͑b͒ in a DAC that is heated internally with a laser, 15 and ͑c͒ in a DAC that is heated externally through a resistive heater such as graphite. Each of these techniques has its advantages and disadvantages.…”

“…Recently, radial diffraction experiments in the DAC using in situ laser heating have made significant progress. 15,16 They are, however, complicated by the presence of large temperature gradients that develop during heating. So far externally heated DACs have not been used for stress and texture analyses because the resistive heater would lie in the x-ray path.…”